In oil and gas wells, fluids and gases are entering the well along the completion interval based on reservoir pressure and permeability distribution, which often is quite non-uniform. Hence the inflow rate at certain sections of the completion can vary greatly, spatially. For reservoir depletion purposes and well integrity issues, it is desirable to create uniform inflow profiles along the well to provide a more even depletion of the reservoir, or to choke back certain high permeability streaks, which otherwise could draw in early water or gas.
To achieve this, the well completion can be divided into compartments, which may be annularly isolated with packers (e.g. swell packers, etc.). The compartment locations and sizes may be chosen based on reservoir pressure and permeability non-uniformities. Inflow Control Devices (ICD) may be employed in those compartments, forcing the incoming flow through a restriction (e.g. nozzle, tubing or tortuous flow path), thereby creating an additional velocity and fluid density dependent pressure drop that will slow down the flow to create the inflow profile desired.
In certain completions, it also may be desirable to perform one or more stimulation operations to stimulate the subterranean formation and increase a potential for production of the reservoir fluid therefrom. These stimulation operations may include providing a stimulant fluid to specific, or target, regions of the subterranean formation and often utilize stimulation ports within the casing string to provide the stimulant fluid from the casing conduit to the target region of the subterranean formation.
Following stimulation operations, it also may be desirable to control a flow rate of the reservoir fluid into the casing conduit during production of the reservoir fluid from the casing conduit. Typically, a desired flow rate of the reservoir fluid into the casing conduit during production from the subterranean formation is significantly lower than a desired flow rate of the stimulant fluid during stimulation of the subterranean formation. Thus, it may be desirable to decrease and/or restrict a flow rate of the reservoir fluid from the subterranean formation into the casing conduit through the stimulation ports.
As such, a challenge with ICDs is that the size of the flow restriction is fixed during the installation process; hence the ICD is optimized for a certain fluid type and narrow production rate range. This can result in issues should the well require stimulation or be treated for scale (e.g. temporary injection of stimulation/scale prevention fluids), or when a production well is converted into an injection well later in its life. The stimulation rates, can be several times higher than the initial production rates, which a) can cause structural failure of the ICDs and b) change the injection profile to a non-uniform or an undesired profile. A possible solution to this problem is to have the ability to provide a certain flow capability during production flow, and a larger flow capability during stimulation/injection.
Currently there are several possibilities in the industry to achieve this. One is the use of controllable inflow devices (ICV) that can be triggered to change their flow area based on operator input from the surface via hydraulic lines, electric lines or even radio-frequency control tags pumped into the well. Another option is to equip the completion with ICDs, but also have sliding sleeves joints which can be opened (in general, mechanically through a downhole setting tool) for stimulation or injection. Both options require the operator to have well intervention accessibility through a coiled tubing tool, electric or hydraulic lines or radio-frequency controlled tags that require the downhole equipment to have batteries.
Another option is to equip the well completion with ICDs for production, but also have additional check valve style devices that allow flow from one direction (e.g. injection), and close them when the well is being put on production. The downside of this approach is the increased risk of mechanical failure due to having a large number of individual components (e.g. ICDs and valves) in the well. As may be appreciated, if some of those check valves do not close after the stimulation/injection process, then the production inflow profile can be greatly compromised.
As such, there exists a need to address the aforementioned problems and issues. Therefore, what is needed is a simple, cost-effective apparatus that provides one integrated device having a certain flow restriction during production, and another flow restriction when the flow direction is reversed.